如何从Firebase存储获取图像url并将值分配给字符串并重用该值

Question

task.addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
    @Override
    public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
        imageurl=taskSnapshot.getMetadata().getDownloadUrl().toString();
    }
});

我想在将对象发布到数据库时在这里使用它：

PostAd pa= new PostAd(auth.getUid(),imageurl,timeStamp);
String id = db.child("Ads").push().getKey();
db.child("Ads").child(id).setValue(pa).addOnSuccessListener(new OnSuccessListener<Void>() {
    @Override
    public void onSuccess(Void aVoid) {
        dialog.dismiss();
        Toast.makeText(getActivity(),"Ad posted succefully",Toast.LENGTH_LONG).show();
        Title.setText(null);
    }
});